Most photographers seek out showy, nectar-drinking insect species near flowers. But one lucky ecologist caught a butterfly and a bee sipping an unusual drink: a caiman’s tears.

Carlos de la Rosa of La Selva Biological Station in Sarapiquí, Costa Rica, spotted the interaction in December, on the shores of the Puerto Viejo River near the station. He observed a bright orange Julia butterfly, Dryas iulia, and a solitary bee in the Centris genus hovering around the eyes of a spectacled caiman, Caiman crocodilus. The insects fed on the tears of the crocodilian, a “lacryphagous” behavior to obtain salts and proteins that are rare in a plant-based diet.

De la Rosa’s observation appears in the May Frontiers in Ecology and the Environment. He is not the first to observe insects using animals as a salt lick. For instance, researchers reported a solitary bee drinking the tears of a yellow-spotted river turtle in Ecuador in 2012.